Function surface_strike_grid_from_deltas 

pub fn surface_strike_grid_from_deltas(
    market: &SurfaceMarketContext,
    expiry: SurfaceTenor,
    absolute_deltas: &[f64],
    option_type: OptionType,
    convention: SurfaceDeltaConvention,
    volatility: f64,
    model: PricingModel,
) -> Result<Vec<SurfaceDeltaStrike>, FerroRiskError>